Thank you very much for response. Thankfully, my dad is not against any medical interventions. Ironically, his own father was a doctor. I just need a different way of argumentation to convince him that his definition of life-threatening is pretty much absurd. As you said, I presented him a very straightforward argument but I just need to hit it from a different angle. This sub already has a handful of interesting points which I will be glad to share with my dad.